Ignition-governing apparatus



Aug. 20, A. KENT IGNITION GOVERNING APPARATUS Filed June 25. 1921 2Sheets-Sheet l WUZ I mi ATTORNEY.

Aug. 20, 1929.

A. A. KENT IGN'I TI ON GOVERNING APPARATUS Filed June 25, 1921 2Sheets-Sheen 2 65 who who 2000 nice eooa zA/qwvz SPEED INVEN TOR.

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Patented Aug. 20, 1929.

ARTHUR ATWATER KENT, F ARDMORE, PENNSYLVANIA.

IGNITION-GOVERNING APPARATUS.

Application filed June 25, 1921. Serial No. 480,315.

My invention relates to apparatus for automatically governing theproduction of ignition sparks for internal combustion engines,particularly a variable speedengine such as employed upon motorvehicles, or in like relations.

In accordance with my invention, there is utilized a centrifugal orautomatic gover-' nor of very small weight, mass or inertia,particularly as to the governor late or member, and the weights carriedsolely thereby, secured to the system, comprising an ignition-timing camor equivalent and the usual distributor, for angularly adjusting thatsystem, in response to speed changes, with respect to the engine drivenor timer shaft to which latter the other of the governor plates ormembers is' secured, and with which the cam and distributor system iscoaxial. r

In accordance with my invention, the cam and distributor system has amass, weight or inertia which is so large a proportion of the mass,weight or inertia of that system and the thereto attached governor plateand weights, that, throughout the range of angular adjustment of thesystem with respect to the timer shaft in response to changes of speedof' that shaft, the adjustment is smooth and regular, and overcomes theerratio or irregular behavior which characterizes the same structure butwith the weightciilrrf'ying governor plate secured to the timer s a t.For an illustration of one of the various forms my invention may take,reference is to be had to the accompanying drawings, in.

which:

Fig. 1 is a plan view of interrupter structure. c

Fig. 2 is a verticalsectional view on the line 2-2 of Fig. 1. A

, Fig. 3 is a top plan view of structure shownin Fig. 2 with the topplate removed. Fig. 4 is an inverted plan view of the governor structureshown in Figs. 2- and 3.

Fig. 5 is a perspective view of the system comprising the timer cam or.equivalent with attached weight-carrying governor plate. 0 Fig. 6 is apersplective view of the driving I or timer shaft wit attached co-actinggovernor plate.

Fig. 7 is a perspective view of one of the governor weights.

Fig. 8 is a sectional view illustrating the integral punched pivot.

Fig. 9 comprises characteristic curves explanatory of my invention.

Referring to the drawings, 1 is a'metallic casing having an integralmachined cylindrical hub, 2 whereby the structure is supported andcapable of rotation in a suitable supporting member, not shown. The hub2 is bored to provide bearings for the engine driven or timer shaft 3having at its lower end the tongue or lug 4 whereby the shaft 3 .isdriven by and in suitable fixed relation with the internal'combustionengine whose ignition is controlled by the shaft 3. The speed of theshaft 3 is generally half that of the crank shaft of the engine when thelatter is of the four cycle or four stroke typp.

Rigidly secured to the shaft 3, as y shrinking it thereon, is thesmaller, lighter, or secondary governor plate 5, in this instance shownas stamped from sheet steel of suitable thickness. In the periphery ofthe plate 5 is a plurality of notches or recesses 6, preferablyuniformly circumferentially spaced. Integral with the plate 5 is theupstanding lug 7 hereinafter referred to.

, The shaft 3 at its upper end is reduced in diameter to for'm thebearing member 8 for the sleeve 9, integral with which or upon which issecured the cam 10 having as many points as there are cylinders of theengine; in the example illustrated, the cam is suited for a four-clinder engine. The sleeve member 9 exten s freely through an opening 11in the plate 12 secured upon the upper edge of the casing 1. Securedupon the plate 12 is the bracket 13, to which is secure a leaf spring 14which supports the movable interru ter arm 15 having the fibre shoe orcam f0 lower I6 actuated by the cam 10 as it rotates to move the movableinterrupter contact 17 away from the stationary interrupter contact 18,the spring 14 returning the contact 17 into engagement with the contact18 as and whenpermitted by the cam 10. The interrupter contacts areshunted by a condenser contained in the structure 19.

The cam sleeve 9 is slotted at its upper and a 2 to receive and drivethe high tension distributor, not shown, as well understood in the art.I

Rigidly secured to the cam sleeve 9, as

-by shrinking it thereon, is the main or material and construction.

primary governor plate 21, of any suitable In the example illustratedthe plate 21 is stamped from sheet steel of suitable thickness. Uponeach of .a suitable number of pivots 22 is pivoted a movable arm orgovernor weight 23 having an inwardly projecting arm 24 having a roundedend 25 engagin in a notch 6 of the secondary governor p ate 5. In theexample illustrated, each governor weight 23 is formed of sheet metalandbent'to U- shaped form as indicated at 26, Fig. 7, whereby eachweight 23 embraces the edge of the governor plate, 21 To the ear 27 ofeach weight member 23 may be attached at a hole 27 in car 27 one en'd ofa sprlng 28, whose other end is attached to the plate 21 at a hole 29therein.

While each governor weight may be provided with a spring, as stated, Ihave found...

. the notch, aperture or other suitable formation 30 in the plate 21,the lug 7 being bent over the plate 21, thereby preventing separation of.the plates 5 and 21 from each other'in a direction longitudinallyof theaxis of rotation of the shaft 3. The angular extent about the axis ofthe shaft 3 of the notch 30 is made such as to permit sufficient angularmovement of the plate 21 with respect to the plate 5 and shaft 3 and yetlimit such angular adj ustinent'or movement.

'lVhile at 22 separate pivot pins may be provided, it is preferred, asindicated in Fig. 8, that the pivots 22 shall be integral with the plate21 and formed by placing the plate 21 over a die member 31 havingtherein a circular hole of the diameter which the pivot s to have. Thereis then brought down upon the plate 22 by any suitable means a: punch 32which is forced-only part way through the plate 21, forcing out into thehole in the die member 31 the integral pivot 22. By preference the punch32 has a diameter greater than that of the pivot 22. to be formed,whereby without passing too far through the plate 21 the unch 32displaces suf iicient metal to form t e pivot 22 ofsuffiClOIlildlEtIIlBtGI and height or length below .the surface of theplate 21. The pivot 22 is in effect a punching from the plate 21 whichhas not been completely dislodged or severed therefrom, but remains inpart within the plate. in the process of formation, and its attachmentto the plate 21 is more firm and secure than in the case of separateinserted pivots. Pivots formed as described have the advantage that theydo not work or jar loose in service, as is the case with insertedpivots. Furthermore, by the structure described the The pivot itself ishardened cost of production is materially decreased.

. The operation isas follows:

As the shaft 3 is driven or rotated bythe engine in fixed angularrelation with respect to the engine shaft, the governor plate 5 isrotated at like speed. Rotation is communicated to the arms 24 of thegovernor weights and through them to the governor plate 21, with whichrotates the sleeve 9 and there fore the timing cam-10 and thedistributor, not-shown, carried at the upper end of the sleeve 9 androtated thereby. Preferably, until a predetermined speed is attained,the plate 21 is positively driven by engagement of plate 5 with lug 7,and thereafter the governor acts and advances plate 21, until at'suitably high speed advance of plate 21 and cam 10 is limited byengagement of lug 7 with the other end of aperture 30.

With increasing speed the weights 23 r0;

tate on their pivots 22, the centrifugal force causing theweights 23 tomove outwardly in opposition to the tension exerted thereon by thespring or springs 28. Such pivotal movement of the arms 23 upon theirpivots 22 causes rotation of the plate 21 with respect to the plate 5,and such rotation of the plate 21 effects a rotation of the cam 10 withrespect to the shaft 3, thereby advancing the ignition as the speed isincreasing, and retarding the ignition as the speed decreases.

In a general or broad sense, the operation above described is thatheretofore known in the art. I have found, however, that by reversingthe relation of the governor plates, as 5 and 21, as herein described,that is, by attaching the main governor plate carrying the weights tothecam or its equivalent, thereby producing a movable cam system or unitof considerably greater weight and inertia, and by applying the othergovernor plate, as 5-, to the driving or timer shaft, as 3, the advanceof the cam ahead of the shaft 3 with increasing speed is regular andsmooth, for example, as indicated by the characteristic curve A, Fig. 9,wherein abscissae are speeds of the engine crank shaft and ordinates aredegrees of advance of the cam 'with respect to the engine crank shaft.The curve A is to be contrasted with curve B, which indicates a mode ofbehavior where the plates 5 and 21 are reversed, that is,

i C, on curve B, it will be noted that with increasing speed the cam isadvanced, but that upon reaching a certain speed range the cam isactually retarded throughout a small speed range and thereafter is againadvanced with increasing speed. The behavior as indicated at C isirregular or erratic, and is undesirable, and I have found that byreversing the relation of the governor plates 5 and 21 and employingthem as herein described, the defects of performance indicated by curveB are overcome and the smooth and regular performance indicated by curveA is procured.

As a matter of belief merely, and without prejudice, it appears thatwhen the plate 5" is attached to the cam and the weight-carrying plate21 is secured to the timer shaft, as 3, the cam system or unit has sosmall inertia or mass that the spring 14 of the light movableinterrupter structure comprising the arm 15 is able, at a certain speedor within a certain speed range, artificially to advance the cam systemindependently of;

the action or control of the governor by forc ing the cam shoe 16against the am immediately after a high point, as 10 on the cam haspassed the shoe 16, such pressure of the shoe 16 u on the cam thenforcing the cam system a ead or advancing it, this being possiblebecause of lost motion, however slight, between the parts of thegovernor structure. Or, differently stated or viewed, the pressure ofthe cam shoe 16 upon the cam 10 produces a drag or braking effect uponthe cam system or unit, and due to irregularities, unevenness orvariations in such drag or braking effect, there occurs crratio orirregular behavior, such as indicated at C on curve B. By imparting tothe cam system or unit sufficient mass, it ossesses sufiicient inertiaagainst or success ully resists the effects of such irregular orvariable braking or drag so that regular performance such as indicatedby curve A as procured. For brevity, this inertia is referred to asangular inertia, in the sense that the inertia opposes sudden motion ofrotation or angular adjustment of the cam unit or system.

The herein described governor is characterized by very small weight ormass, parti'cularly as to the plate or member 21 and the thereto pivotedor attached weights 23. It is in the use of such a light weightrgovernorstructure that the attachment of the weight-carrying governor plate tothe cam and distributor system is of significance in procuring thesmooth and regular angular adjustment in response to speed changes. Thisgovernor plate and its attached weights together with the cam anddistributor system have a combined weight, mass or inertia of which theweight, mass or inertia of the cam and distributor s stem is so great aproportion that the a oresaid smooth and ever, as to their applicationto cam and timing shaft, as herein disclosed, the advance of the'cam isperfectly controlled, presumably because of the'greater mass or inertiaof the system, comprising the cam, distributor, the main governor plateand the governor weights.

What I claim is:

1. Ignition timing apparatus comprising an engine driven shaft, a s stemcoaxial with said shaft, angularly a justable with respect thereto andcomprising an ignitiontiming cam and a distributor, a governor plate ofsmall mass secured to said system, centrifugally operated weights ofsmall mass mounted solely upon said governor plate, a second governormember secured to said shaft, and resilient means opposing movement ofsaid weights in their action in rotating said system with respect tosaid shaft, said system, governor plate and weights having a mass ofwhich the mass of said system is so large a proportion that the "angularadjustment of said system with respect to said shaft is regular,throughout the range of adjustment, with change 0 speed of said shaft.

2. Ignition timing apparatus comprising i nor plate, a second sheetmetal governor plate secured to said shaft, said governor platesdisposed closely adjacent each other,

and resilient means opposing movement of said weights in their action inrotating said system with respect to said shaft, said s stem, firstnamed governor plate and weig ts having a mass of which the mass of saidsystem is so large a proportion that the angular adjustment of saidsystem with re-' spect to said shaft is regular, throughout the range ofad'ustment, with change of speed of said sha t.

- 3. Ignition timing apparatus comprising i an engine driven shaft, anaxially short governor of light weight, a system coaxial with saidshaft, angularly adjustable with respect thereto and comprising anignition-timing cam and a distributor, said governor comprising twosheet metal plates secured respectively to said shaft and to saidsystem, weight structure of small mass pivoted to that governor platewhich is secured to said system, the entire weight structure of thegovernor carried solely by said last named governor plate, resilientmeans opposing movement of said weight structure in adjusting saidsystem angularly with respect.

to said shaft, said system, last named g0v'- ernor plate andweightstructure having a.

mass of which the mass of said system is so 'ment of said system withrespect to said.

shaft is. regular, throughout the range of'10 adjustment, with change ofspeed of said shaft. A

"In testimony whereof I have hereunto affixed my signature this 23rd dayof June,

' ARTHUR ATWATER KENT.

